Steel retainer



April 1, 1930. F. H. THQMAS 1,753,034

STEEL RETAINER Filed Dec. 21, 1927 D F A Patented Apr. 1, 1930 UNITED STATES PATET OFFICE v FLOYD H. THOMAS, F MILAN, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COM- IPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY STEEL RETAINER Application filed December 21, 1927.

This invention relates to rock drills, but more particularly to a steel retainer for fluid actuated rock drills of the hammer type.

The objects of the invention are to maintain the drill steel in the front head, to enable the steel retainer to be readily attached 011 a rock drill and removed therefrom without the aid of special tools or appliances and to assure against accidental oscillation of the 19 retainer out of the operative or retaining position.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating a practical application of the invention,

Figure 1 is an elevation of the front end of a rock drill having the invention applied thereto,

Figure 2 is a sectional elevation of the front 20 end of a rock drill showing a side View of the retainer, and

Figure 3 is an end View showing the manner in which the yoke cooperates with the collar of a drill steel for preventing ejection of the drill steel from the front head.

Referring to the drawings, the invention is shown embodied in a rock drill, only the front head A and a portion of the cylinder B of which are shown. The front head A and the cylinder B are held in assembled position by spring pressed side bolts C, only one of which is shown.

The front head A and the cylinder B in this instance are centralizedwith respect to each other by a front cylinder washer D which has a bore E adapted to receive and guide an anvil block F. The anvil block F projects with its rearward end into the front end of the cylinder to receive the blows of a hammer piston Gr reciprocable in the cylinder B. Such blows are transmitted by the anvil block F to a drill steel H extending into and guided by the front head A. The drill steel H has a collar J which abuts the front end of the front head to limit the distance which the drill steel may extend into the front head.

Near the front end of the front head A are a pair of trunnions K. The trunnions K are disposed on opposite sides of the front head and are off-set with respect to the longitudithe Serial No. 241,557.

nal axis thereof. Preferably the trunnions K form a part of bosses or lugs L having flat sides 0 which merge into and are tangent to the periphery of the front end of the front head A.

In accordance with the present invention, means are provided for preventing ejection of the drill steel H from the front head. These means in the present instance comprise a yoke P which partly encircles the drill steel forwardly of the collar J and a pair of integral side arms Q extending rearwardly from' the ends of the yoke P, said yoke and said side arms being formed from a sheet metal blank. The side arms Q have straight portions R adjacent the yoke and parallel to the drill steel so spaced with respect to each other that the distance therebetween is somewhat smaller than the diameter of the collar J. Due to this spacing of the side arms both of the straight portions R of the side arms Q, may slidably engage the collar J for preventing the yoke'from being accidentally oscillated out of the retaining position.

The side arms Q, carry at their rearward ends outwardly extending flanges S in which are formed apertures T. The apertures T are adapted to receive bolts U forming a part of bearing blocks V, said bearing blocks V having holes W' to receive the trunnions K 011 which the bearing blocks are pivoted. In this position the bearing blocks are adapted to bear against the fiat surfaces of the lugs formed on the front head. At the forward end of the bearing blocks V are formed flat seating surfaces X for the flanges S. Springs Y encircling the bolts U are seated with one end on nuts Z threaded on the bolts and press with their other ends against the flanges for absorbing the blows of the drillsteel againstyoke P.

To the end that the yoke P will at all times remain in the retaining position, the bearings V are provided with shoulders Z) adapted to engage the front end of the front head A. 95 By forming shoulders Z) on opposite sides of the bearings V the period of usefulness of the bearing blocks may be greatly prolonged since when one shoulder b becomesworn and H unfit for use, it will be merely necessary to reverse the bearing blocks on the trunnions K.

As will be observed, the rearward ends of the bearing blocks V are of cylindrical formation and have no projections extending rearwardly of the retainer. Due to this construction the retainer is particularly adapted for use on rock drills of the type supported by shells and in which case such shells frequently act as an obstruction to the movement of the retainer.

In assembling the retainer on the rock drill, the bearing blocks V may first be placed on the trunnions K in such a position that one or the other of the shoulders Z) lie against the front face of the front head A. After the bearing blocks have been thus disposed, the yoke P may be placed on the bolts U and the springs Y and the nuts Z may then be also placed on the bolts to press the flanges S against the surface X of the bearing blocks.

In the operation of the drill, whenever it is desired to remove-the drill steel H, the yoke Pimay be rocked from the retaining position to a position such as that indicated by dot and-dash lines in Figure 2. In this position of the retainer, the yoke P may be removed from the :path of the collar J and the drill steel H may then be removed and another drill steel substituted therefor. After such replacement of the drill steel, the yoke P may again'be rocked to the retaining-position wherein it will beheld by the shoulders I) of the bearing blocks V.

I claim: In'a steel retainer for rock drills, the combination of a front head provided with flat surfaces 'on opposite sides of its front end,

cylindrical trunnions disposed on the fiat surfaces, a-drill steel in the front head having a collar, bearing blocks pivoted on the trunnions and having surfaces bearing against the fiat surfaces of the front head,

bolts integral with the bearing blocks and extending forwardly of'the trunnions, a yoke for partly embracing thedrill steel forwardlyof the collar and having a pair'of side arms for attaching said yoke to the front head, said yoke and side arms being formed from a sheet metal blank, said side arms extending rearwardly from the'ends of the yoke, outwardly extending flanges on the ends of the side arms and having apertures to receive the bolts, straight portions on the side arms adjacent the yoke and parallel to the drill steel adapted to slidably engage the collar to prevent accidentaloscillation of :the yoke fromthe retaining position, shoulders on the bearing blocks to engage the end of the front head for holding the yoke in the retaining position, and springson the bolts to absorb the blows of the drill steel against the yoke.

In testimony whereof I have signed this specification.

:FLOYD H. THOMAS. 

